Effects of body composition on metabolism in deer mice ranging in age from 27 days to 1827 days
| V̇O2max | V̇O2sum | ||||
|---|---|---|---|---|---|
| BMR | Age < breakpoint | Age > breakpoint | Age < breakpoint | Age > breakpoint | |
| Body composition | (N=54) | (N=25) | (N=30) | (N=25) | (N=30) |
| Heart mass | r=0.337, P=0.0145* | r=0.642, P=0.00126* | r=0.236, P=0.233 | r=0.443, P=0.0387 | r=0.333, P=0.0827 |
| Lung mass | r=0.266, P=0.0565 | r=0.604, P=0.00287* | r=0.358, P=0.0612 | r=0.420, P=0.0515 | r=0.392, P=0.0394 |
| % fat content | r=0.298, P=0.0320 | r=0.601, P=0.00307* | r=0.128, P=0.516 | r=0.439, P=0.0408 | r=0.424, P=0.0245 |
| Hematocrit | r=0.280, P=0.0443 | r=0.413, P=0.056 | r=0.231, P=0.237 | r=0.462, P=0.0305 | r=0.347, P=0.0705 |
BMR, basal metabolic rate; V̇O2max, maximal oxygen consumption in exercise; V̇O2sum, maximal oxygen consumption in thermogenesis.
Age breakpoints for V̇O2max and V̇O2sum (485 days and 483 days, respectively) were obtained from the complete data set (Table 2). Regressions were based on loge-transformed metabolic data and included the effects of loge-transformed lean tissue mass and age. Partial r and P values are shown; P values that remained significant after Bonferroni correction are indicated with asterisks (adjustedα =0.0167 for BMR and 0.0036 for V̇O2max and V̇O2sum).